1. Field of the Invention
The present invention relates to a method for preventing, alleviating or treating a liver disease and, more specifically, to a method for preventing, alleviating or treating a liver disease, comprising administering a composition comprising a Triticum aestivum Lamarck leaf extract or a fraction thereof to a subject in need thereof.
2. Description of the Related Art
The liver is an important organ that is responsible for metabolism of various nutrients and hormones introduced into the body as well as for detoxification of harmful substances. Due to the buffering effect of the liver, minor damage to the liver by hepatotoxic factors can be recovered and does not develop into liver disease. However, persistent liver injury due to continuous exposure to excessive intake of drugs or alcohol, stress, etc. may lead to inflammation of the liver and is highly likely to develop into a series of chronic liver diseases such as chronic hepatitis, cirrhosis, and liver cancer.
It is known that liver injury is mainly caused by depletion of antioxidant enzymes due to oxidative stress and by dysfunction of hepatocytes that can prevent liver injury. Moreover, apoptosis of hepatocytes is involved in almost all types of human liver injuries and is an important parameter for the detection of acute and chronic liver diseases including liver injury induced by viral and bacterial infections, exposure to toxic substances, metabolic dysfunction, autoimmune reaction, etc. Many clinical studies and animal models have reported that apoptosis of hepatocytes is an important factor in the development of liver diseases including inflammation, hepatic fibrosis, cirrhosis, and liver cancer.
Examples of substances that cause liver injury include lipopolysaccharide (LPS), alcohol, acetaminophen, carbon tetrachloride (CCl4), D-galactosamine, bromobenzene, etc.
The liver is the organ that mainly acts on the removal of endotoxins that enter the body, and thus the penetration of endotoxins into the body causes liver injury. Among others, lipopolysaccharide (LPS) is one of the substances, which constitute the cell wall of Gram-negative bacteria, and interacts with toll-like receptor 4 present in Kupffer cells and other cells to increase the production of proinflammatory cytokines such as tumor necrosis factors (TNF-α), interleukin 1 (IL-6), and interleukin 6 (IL-6), thereby causing oxidative stress and inflammatory responses, leading to liver injury.
Moreover, the liver is the major organ of alcohol metabolism, and after intake, alcohol is converted to acetaldehyde by alcohol dehydrogenase, CYP2E1 and catalase. Excessive intake of alcohol causes excessive acetaldehyde production, which inhibits the production of antioxidants such as glutathione (GSH) that reduces oxidative stress, leading to liver injury, which increases the risk of alcoholic liver diseases such as cirrhosis, and liver fibrosis.
In addition, excessive intake of acetaminophen, a drug component that inhibits the biosynthesis of prostaglandin in the body to exhibit an analgesic effect, causes liver injury. When absorbed into the body, acetaminophen is detoxified with a combination of gluconic acid and sulfate, and a portion thereof is converted to N-acetyl-p-benzoquinoneimine to exhibit hepatotoxicity, which is neutralized by antioxidant enzymes such as glutathione. However, excessive administration of acetaminophen produces a large amount of N-acetyl-p-benzoquinoneimine, which causes depletion of glutathione in hepatocytes and apoptosis of hepatocytes due to cytotoxicity, leading to liver injury.
Chronic liver injury is often not recognized until the liver loses its functions of detoxification and protection and is a major cause of liver diseases. Interferon, ursodeoxycholic acid, silymarin, vitamin B, etc. have been used for the treatment of hepatitis and cirrhosis and for the improvement of liver function, but there is a lack of naturally occurring materials which can be safely ingested and activated to improve liver injury.
Meanwhile, Triticum aestivum Lamarck is one of the main crops produced worldwide and produces useful components during germination, and Triticum aestivum Lamarck leaves refer to those sprouting from Triticum aestivum Lamarck.